A gas turbine engine typically includes a fan section, a compressor section, a combustor section, and a turbine section. A fan section may drive air along a bypass flowpath while a compressor section may drive air along a core flowpath. In general, during operation, air is pressurized in the compressor section and is mixed with fuel and burned in the combustor section to generate hot combustion gases. The hot combustion gases flow through the turbine section, which extracts energy from the hot combustion gases to power the compressor section and other gas turbine engine loads.
Increasing engine bypass ratios and/or the electrical needs of an aircraft tends to increase demand on the engine's compressor section to perform under increased loading. In this regard, it may be desirable to transfer load from the high spool to the low spool for accessory power generation to reduce idle thrust and core temperatures and/or to decrease fuel consumption. However, the low spool tends to experience a wide range of rotational speeds, which can be problematic for accessories (e.g., generators and/or pumps) that need a relatively constant speed.